Easy and safe angiography has become feasible as a result of technical advances, development and improvement of radiographs and development of safe contrast media. Anglographic methods are roughly divided into two types: arterial angiography and venous angiography, including (1) methods in which the artery or vein is directly perforated percutaneously (carotid arteriography, vertebral arteriography, femoral arteriography, brachial arteriography, pelvic venography, lower limb venography), (2) methods in which the artery or vein is surgically exposed, incised and catheterized for imaging (cardiovascular angiography, inferior vena cava venography, pulmonary arteriography), (3) methods in which a catheter is inserted percutaneously by the Seldinger technique (peritoneal arteriography, abdominal aortic arteriography, renal arteriography, inferior vena cava venography, hepatic venography) and (4) methods in which a contrast medium is injected to the vein or artery and the arterial or venous phase is photographed. The development of the Seldinger technique made possible percutaneous intravascular catheterization (intravascular catheterization requires a surgical procedure in prior art methods), leading to remarkable advances in angiography.
Objectives of angiography include 1) qualitative and quantitative evaluation of lesions in blood vessels, 2) qualitative and quantitative evaluation of lesions in various organs and surrounding tissues on the basis of vascular exclusion and/or invasion pictures, 3) dynamic and functional evaluation of blood vessels by continuous imaging of contrast medium flow, and 4) anticancer agent injection to lesions via blood vessels. Advances in imaging techniques have markedly improved bypass (shunt) surgical treatment. Bypass surgery, a type of blood route reconstructive surgery for obstructed blood vessels, constructs a bypass from the proximal to distal sides of the obstructed portion (bypass transplantation), including aortocoronary bypass, aortoiliac bypass and cardiopulmonary bypass.
However, vascular perforation in angiography and vascular cutting, suturing etc. in bypass surgery can cause vascular hypertrophy, since they affect the blood vessel by direct physical stimulation.
Compounds exhibiting angiotensin antagonistic action, used in the present invention, are known to serve as therapeutic agents for circulatory diseases such as hypertension, heart diseases (heart hypertrophy, heart failure, myocardial infarction etc.), cerebral stroke and nephritis (e.g., Japanese Patent Unexamined Publication No. 364171/1992). Concerning their mechanism of action, inhibition of the binding to angiotensin receptors of angiotensin , a potent vasoconstrictor, has been suggested.